Following the results on Sunday Macri vowed to'redouble his efforts to ensure victory in October

After learning of his broad lead with more than 47% of votes for the "Frente de Todos" (Front for All) party he represents, the aspirant to the Presidential Palace offered several messages to the Argentine people.

President Macri, at left with running mate Miguel Angel Pichetto, speaks at his party's headquarters Sunday after primary elections. He says he is taking the necessary, painful steps to get the economy going after 12 years of leftist populism under Cristina Fernandez and her predecessor and late husband, Nestor Kirchner.

Speaking in Buenos Aires after the result Mr Fernandez said: "Argentinians realised we are the change, not them", and vowed "to end this time of lies and give a new horizon".

The Fernandez ticket, whose two members are not related, contends Macri must be defeated to fight the poverty and homelessness that they blame on his policies. "The markets are giving warning that the government has put itself in a position it can not respond to", Fernandez told Radio 10.

Argentina is now in a recession and posted 22 per cent inflation for the first half of the year - one of the highest rates in the world.

Poverty now affects 32 percent of the population. The peso has lost nearly one-third of its value so far this year, making it the worst performing currency in the world.

Backed by the International Monetary Fund, Macri has initiated an austerity plan that is deeply unpopular among ordinary Argentines, who have seen their spending power diminished dramatically.

The Buenos Aires stock exchange actually shot up eight percent on Friday amid expectation that Macri would do well in Sunday's vote.

The worst-hit shares lost nearly 50 per cent of their value.

Argentina's main political parties have already chosen their presidential nominees, allowing the primary to serve as the first concrete measure of voter sentiment after opinion polls showed a narrow margin between Macri and Fernandez.

Political analyst Sergio Berensztein described it as the government's "worst political crisis". If there is no clear victor, voters will return for a run-off on November 24.

To be elected president in the first round, candidates need to finish with at least 45% of the votes or have 40% and a greater than 10-point advantage over the nearest rival. "We always fix the problems that others create", said Fernandez to thousands of cheering supporters in Buenos Aires on Sunday night. There could be an even stronger degree of market volatility if final results show that Fernandez has enough support to clinch the presidency in October's first round, analysts said.